Like Captain Ahab in Moby Dick, paleontologists have long been on the track of a giant sperm whale, one armed with large, flesh-tearing teeth. They knew such a creature existed, because for more than a century they've found isolated specimens of its teeth at various sites worldwide. Now scientists, exploring sediments off the coast of Peru, have discovered the first fossilized skull and jaws (and some teeth) of this ancient leviathan. The 13-million-year-old sperm whale stretched some 13 meters in length—about twice as long as a great white shark, Carcharodon carcharias, but 5 meters shorter than today's modern giant sperm whale, Physeter macrocephalus. Despite their shorter length, the ancient whales were top predators, equipped with upper and lower sets of knife-edged teeth, some as long as 36 centimeters. Today's giant sperm whales have only tiny teeth along their lower jaws, and are suction-feeders, ingesting deep-water cephalopods. Their ancient cousins' dining habits were more like those of killer whales: they ate other whales. The researchers, who will report their finding tomorrow in Nature, have named the new whale Leviathan melvillei, in honor of Herman Melville, the author of Moby Dick.